One mole of an ideal gas undergoes a cyclic process (ABCDA) starting from point A through 4 reversible steps as shown in the figure. Total work done in the process is
1
\(\rm R\left(T_1-T_2\right) \frac{V_2}{V_1}\)
2
\(\rm R\left(T_1+T_2\right) \frac{V_2}{V_1}\)
3
\(\rm R\left(T_1+T_2\right) \ln \frac{V_2}{V_1}\)
4
\(\rm R\left(T_2-T_1\right) \ln \frac{V_2}{V_1}\)